/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors 
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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package org.hisp.dhis.commons.jackson.jsonpatch.operations;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.core.JsonPointer;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.MissingNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import org.hisp.dhis.commons.jackson.jsonpatch.JsonPatchException;
import org.hisp.dhis.commons.jackson.jsonpatch.JsonPatchOperation;

/**
 * Removes a value (can be a item in a list, or just a plain property).
 *
 * @author Morten Olav Hansen
 */
public class RemoveOperation extends JsonPatchOperation {
  @JsonCreator
  public RemoveOperation(@JsonProperty("path") JsonPointer path) {
    super("remove", path);
  }

  @Override
  public JsonNode apply(JsonNode node) throws JsonPatchException {
    if (path == JsonPointer.empty()) {
      return MissingNode.getInstance();
    }

    if (!nodePathExists(node)) {
      return node;
    }

    final JsonNode parentNode = node.at(path.head());
    final String rawToken = path.last().getMatchingProperty();

    if (parentNode.isObject()) {
      ((ObjectNode) parentNode).remove(rawToken);
    } else if (parentNode.isArray()) {
      ((ArrayNode) parentNode).remove(Integer.parseInt(rawToken));
    }

    return node;
  }

  private boolean nodePathExists(JsonNode node) {
    final JsonNode found = node.at(path);
    return !found.isMissingNode();
  }
}
